I picked mine up for less than $250. I already have a 14", 6", and 80mm. This has to be the most fun I have every had with a scope. It is easy to use, relatively easy to transport, and it performs better than I expected. No, in the sense of quality, this is not a great scope, but it has to be one of the best values out there.

Can't add much to what's already here--good scope, mediocre mount---except to recommend that you run, not walk, to your friendly Sirius Optics dealer and get the Minus Violet filter for this scope. The views of the Moon at 200x are worth it all by themselves. Color fringing, while not at all severe for this achromat, really cuts ointo the sharpness of the image at high power. The MV filter does a most impressive job of sharpening things up.

Hello everyone. Just spent 3 nights with C102GT that I acquired with a Twilight 1 mount. What do I think?

->Cheap, only paid 150 with rings, dovetail, and handle. Cash ;)->Decent optics. CA is terrible on bright stars like sirius at high power, like a freak show going on above me. I was afraid to even look at Jupiter, but fortunately, Zeus looked really good - 4 stripes, grs, and darkening of poles which is good enough for me in a 4-incher (My ST80 only showed 2 stripes in comparison). Also, not a lot of CA on Jupiter and the other planets, but stay away from bright stars with this scope unless you have a minus-violet filter.->Nice focuser. Its a 2-inch rack and pinion, but wow, very smooth after some adjusting with no image shift. Nice focuser wheels, too.->Its a long F10 so its need a good mount and a wind-free lifestyle.->Overall, I like the scope, and its definitely the best affordable 4 inch planetary/double star scope out there still but fans of the 100mm mak might disagree. I like them both, but the C102 is cheaper and its images are crisper. My friend and I recently had the chance to compare the C102 and with his C6; his had more detailed views but the long tube seemed to attract more people to me.

I've been using this nifty refractor for about two years now and have found the experience delightful. A perfect telescope? Hardly. A great astro-toy? Absolutely! There are many good suggestions posted on the web on how to modify the scope to make it better. Read these and make modifications as you desire. If you're an avid amateur looking for a good scope for under $500, you'll be hard pressed to do better than this.

These are now the Celesron C4-R, wanted a Refractor with locked in optics and good planetary views that was still portable. Is slightly heavy but can be carried in one piece around the yard. The optics are very good, as mentioned by others tripod is abit shaky noticed at high powers 160X and above tho does still work. Slow motion controls work well tracking the planets, does a nice job at 160X. Even though an F/10 still suffers with some chromatic distortion, see a purple like hue however just effects the very brightest Stars, Jupiter and the moon, I don't find it much of a problem. Deep Sky Objects within its aperature are fine, example open clusters fill the field with jewel like stars, absoutely great. Surprised at the clarity of the given 20mm 50X silver eyepiece. Finder is abit small, may want to replace it with slightly larger, example 50mm 2 inch one would do a better job. Not going to sell my ETX90 w/Goto as is even more portable, but wouldn't trade this Refractor for the unobstructed views (no secondary blocking front objective) and its Value price, example mine was $399 no postage cost to my door, have seen adds as low as $379 ! If you want a Value portable Refractor, look no further !!

I recently bought a C102-HD OTA used, and I'm very pleased with it. It's the model with the 2" focuser, and the only plastic on the scope was the focus knobs (which I replaced with aluminum ones). The views are very good and chromatic aberration is not too severe. The brightest stars show a fair amount of color, but Jupiter hardly shows any purple at all. (I recently bought this scope, so I haven't had a chance to view the other planets yet.) There is a violet halo around the limb of the moon. I used to have a V-block filter, but I sold it after getting an Orion ED80. I may pick up a new filter sometime in the near future to see how much of the false color it kills.

Stars are nice & sharp with almost textbook-quality diffraction patterns. Star testing shows what I believe to be a bit of spherical aberration, but I'm no expert at star testing! I did notice a bit of astigmatism, but I've been tinkering with the lens & lens cell a lot, and my tinkering seems to have corrected the astigmatism.

I have this scope mounted on a SkyView Pro mount, and it's a very stable setup. Vibrations dampen anywhere from 1 to 2 seconds.

This is a very good achromat, and I'd recommend it to anybody wanting a nice, low-cost, classical refractor.

I selected this scope in an attempt to balance portability, good optics, and price. Celestron's $99 accessory package and a price of $399 for the scope pushed me over the edge. I hope to add an RA drive and 90 degree finder to complete the setup. So far, I have not been disappointed. Views have been sharp, though not as detailed as I had hoped. Tracking is a real improvement over my dob reflector for planets. Mount is stable. Tripod is not when fully extended. This version of the C102HD comes with a collimatable lens cell and spring loaded finder scope adjustment like the Chinese scopes from Orion. which was a pleasant surprise. This is my first refractor, so my vote may be skewed by simple enjoyment of a new experience.

I've had this scope for a little over a year now, and I've had no problems with it. I've never had a problem splitting any doubles or getting crisp images of planets on low power magnifications. Of my three scopes, this one is definitely my favorite.

I have the older, although still Chinese vesion of the scope with the alluminum lens cell.

As recieved, the scope had alot of trouble splitting even easy doubles. Stars were fuzzy on the edges even at low mag, although not especially distorted. Planets refused to focus down well at anything above low mag.

I checked the clamp ring for the lenses, and it was incredibly (and unnecessarily) tight. Lossening this seems to have fixed most of the problems. Images snap into sharp focus, star test is excellent both sides of focus, holds up quite well under higher magnification for the price.

I do have some gripes with the mount, however. Even with everything really tight (especially the the leg mounting bolts), It still has trouble settling down. The dec lock fractured at the end, and the loose piece was trapped inside jamming the head, and causing dissassembly (and no, I did'nt over tighten those fasteners). And the plastic stick on setting cirlce for declination was applied in the wrong position.

I had to do some tinkering, but in the end with some effort, this scope has turned out to be quite the bargain. Although it still needs a better mount.

I was truly surprized and impressed by this scope! I recently had the opportunity to view Jupiter, Saturn and the trapezium through it and it performed far better than I would have ever expected. Jupiter showed 5-6 bands and a crisp shadow of Io transiting the disc at 166x. Saturn showed a clean Cassini Division and at least one band. Sharpness and contrast were very good.Color, while certainly there, was by no means excessive or objectionable - I was too awed by images to really notice it much. Focus snapped in nicely. In the trapezium I could resolve 4 stars, with a 5th flicking in and out, and they were nice pinpoints. I give it a 9 only because the tripod leaves a bit to be desired. This is one nice little scope and for the price it's a real jewel. I think I just might get me one of these!